Field of the Invention
The present invention relates to a waveform data structure, a waveform data storage device, a waveform data storing method, a waveform data extracting device, a waveform data extracting method and an electronic musical instrument for setting different frame sizes depending on tones (waveform types).
Description of Related Art
There are known waveform generating technologies using compressed data structures which can be decompressed by simple configurations. As this type of technology, for example, in JP-B-3826870, there has been disclosed a technology for storing compressed waveform data in frames having a fixed size, and assigning an auxiliary information area and a data area to fixed positions in each frame, and storing auxiliary information and compressed waveform data in those areas, respectively.
According to this technology, even in a case where the numbers of bits of compressed waveform data samples are different, the size of data areas does not vary. Therefore, depending on the numbers of bits of compressed waveform data samples to be stored, the number of compressed waveform data samples which can be stored in one frame varies. Therefore, even in a case where the numbers of bits of compressed waveform data samples are different, since the start positions of frames are arranged at regular memory address intervals, address management becomes easy, and thus it becomes to decompress them with a simple configuration.